Method and apparatus for processing yarn



Aug. 29, 1967 AELJON E TAL 3,337,930v METHdD AND APPARATUS FOR PROCESSING YARN I Filed Jan. 21, 1966 s Sheets-She et 1 Jab/#42:,

V ATTORNEY.

Aug. 29, 1967 METHOD Filed Jan. 21, 1966 II IG.4

R. AELION ETAL AND APPARATUS FOR PROCESSING YARN 5 Sheet -Sheet 2 all llllllllll Illll I I l ll s' ll Ill IMI I N VENTORS.

RENE AELION,

JOSEPH M. Di VERDI, W/L L [AM P. MOYLAN, FREDERICK P. POZNICK BY w/ ATTORNEY.

g- 29, 1967 R. AELION ETAL 3,337,930

METHOD AND APPARATUS FOR PROCESSING YARN Filed Jan. 21, 1966 5 Sheets-Sheet 3 I 76 MFI 78 E if INVENTORS.

JOSEPH M. Di VERDI,

WILL/AM P. MOYLAN, FREDERICK P POZN/CK 54 ATTORNEY.

L 72 I If RENE AEL/ON,

United States Patent 0.

3,337,930 METHOD AND APPARATUS FOR PROCESSING YARN Rene Aelion, Groton, Mass., Joseph M. Di Verdi, Reeds Ferry, and William P. Moylan, Nashua, N.H., and Frederick P. Poznick, Nabnasset, Mass., assignors to Foster Grant Co., Inc., Leominster, Mass., a corporation of Delaware Filed Jan. 21, 1966, Ser. No. 522,177 13 Claims. (Cl. 281) This invention relates to the art of producing crimped continuous filament yarn. More particularly, it relates to a method and apparatus for draw-crimping multifilament yarn such as nylon 6 in a single continuous operation.

It is an object of this invention, therefore, to provide a novel method and apparatus for producing crimped continuous multifilament yarn in a single operation. Another object of this invention is to provide a compact and efiicient apparatus for draw-crimping yarn in one continuous operation. It is a further object of this invention to provide a novel apparatus for heating the yarn in a controlled manner.

Further objects will become apparent from the following description of the invention.

The invention comprises a draw crimper 12 (FIG. 1) having a tensioning device 26, a first set of godet rolls 14, and a heater block 15 which is heated to a temperature of from 140 to 270 F., preferably from 160 to 230 F. The yarn 16 initially comes from a supply package (not shown) and is wrapped around tensioning de vice 26 so that the yarn is held flat against godets 14. The yarn bundle 16 is then wrapped several times around godets 14 and block 15 to uniformly heat the yarn. From this set of godets, the yarn is wrapped around a draw pin 18 and subsequently wrapped several times around a set of draw rolls 20. The second set of rolls 20 is positively driven at a peripheral speed of from about 2 to 9, preferably 2.5 to times greater than the peripheral speed of the first set of godets 14 to stretch the yarn. From the draw rolls 20, the yarn is fed into a stuffer box 22 where it is crimped and set due to the application of further heat, as by superheated steam, subsequent to the yarn leaving the draw rolls 20. Subsequently, the crimped yarn 16b is wound under tension onto a package such as cone 28. The steam is supplied through heater 24 and may be applied to the yarn immediately before or after it is crimped, depending on the characteristics desired. Alternatively, the steam may be applied both before and after the crimping step. I

The time lapse from the initial unwinding of the yarn from the supply package (not shown) to the final windup on cone 28 should not exceed 20 seconds and is preferably in the range of l to 2 seconds. This allows the yarn to be rapidly and efiiciently processed without substantial loss of heat.

The above apparatus and method provide an economical continuous operation which may be operated at high speeds to process up to, e.g. 1500 yards of yarn per minute, and which produces continuous filament textured yarn characterized by high tenacity in the order of 2 to 6 grams per denier, a minimum amount of breakage of the individual filaments of the yarn, good bulk and covering power, and excellent crimp durability and resilience.

This method and apparatus also provide a process which produces close control of thestretching and crimping conditions at several points of operation. By maintaining a homogeneous quality of the yarn and controlling the heat at the first set of bodet rolls by heater block 15, very close tolerances within about :2 F. maybe mainthe rolls 14, thus providing a relatively long residence tained since the yarn is wrapped at least 3 times around 3,337,930 Patented Aug. 29, 1967 time at the heating station. The use of draw pin 18 serves to localize the stress and provide a more uniform cross section to the stretched yarn. It also substantially prevents slippage of the yarn (especially heavy denier yarn) on the first set of rolls 14 since the friction of the yarn on the draw pin 18 provides sufiicient resistance to efiect the stretch. Further steam heating of the preheated yarn provides a very high and durable crimp level. The steam treatment alters the molecular characteristicsof the yarn thereby imparting a permanent set or memory to the crimp. This allows the yarn to be wound under tension to pull the crimp out of the yarn, thus providing a yarn which is easily processed on textile equipment, but which can later be bulked back or recrimped under certain heat and/or moisture conditions to its initial level because of this memory of deformation imparted by the steam treatment. Superheated steam is preferred to other heating agents because its afiinity for nylon allows it to penetrate the fibers and produce rapid heating, and because steam has a very strong crystallizing action on nylon. Also, the resilience and resistance to fatigue of steam treated yarn is quite high. However, other vaporous heating'agents such as oxygen, nitrogen, etc. or mixtures thereof may be used depending on the characteristics of the yarn.

The above process is particularly applicable to multifilament nylon 6 or nylon 66 yarn having from 30 to 250 filaments per bundle, a denier per filament of 6 to 25, and a total denier of to 6250. Such yarns are advantageously used in the manufacture of upholstery fabrics, tufted carpets, etc. However the process is equally applicable to other types of heavy denier multifilament yarns having similar characteristics.

In the drawings:

FIG. 1 represents a schematic view of one embodiment of the present invention, wherein the yarn is set by the application of steam in the stufier box.

FIG. 2 is an exploded view of the steam line 40 showing its connection to the stuffer box 22.

FIG. 3 is a schematic View of an alternative embodiment of the invention wherein the yarn is heated with steam prior to entering the stufi'er box 22.

FIG. 4 is a sectional view showing details of heater 24.

FIG. 5 is an exploded view showing details of the heating box 32. I

FIG. 6 is a rear perspective sectional view .taken along lines 6-6 of FIG. 5 showing the bottom of the heating box 32.

The draw-crimper of the present invention comprises a first set of :godetrolls 14 adapted to receive the multifila ment yarn bundle 16 from a yarn package (not shown). The yarn 16 is initially fed through guides 27a, around tensioning tube 26, and thence through guides 27b and 270. The yarn 16 is then wrapped several times (preferably at least 3 times) around godet rolls 14, and heated due to its contact with heater block 15. It is thence fed around draw pin 18 to localize the stretch applied thereto. From the draw pin 18, the yarn is'fed several times around draw rolls 20. The draw rolls 20 are driven at a peripheral speed ranging from about 2 to 9 times, preferably 2.5 to 5 times the peripheral speed of the first set of rolls 14 to draw out the heated yarn to a length of ranging from 2 to 9 times, preferably 2.5 to 5 times its original length. A draw ratio of 2.5 to 5 is preferred since it allows the yarn to be rapidly stretched in one step.

From the draw rolls 20, the stretched yarn 16a is fed through guide 29, and then by nip rolls 30 into a stuifercrimper of the general type shown in U.S., Patent No. 3,027,619, where it is crimped. To set the crimp in the yarn, superheated steam at a temperature of about 220? to 300 F. is fed into stufi'er box 22 to heat the yarn.

the yarn, but still stays sufiiciently dry to be wound coming out of the stuffer box without any problems. The crimped yarn 16b is subsequently wound under tension into cone 28. The distance between the exit of the stuffer box 22 and the cone 28 should be sufficient to allow time to air cool the yarn to below about 110 F., preferably below 85 F.

In order to provide dry steam to set the crimp and maintain optimum moisture content in the yarn, a novel superheater 24 is provided as shown in detail in FIG. 4. This superheater comprises a hollow cylindrical housing portion 34 having a steam inlet 36 adjacent the bottom 38. A steam conduit 40 is provided adjacent the top of the superheater, to feed the steam into stutter-box 22 through jets 44 (FIG. 2). A screw 46 is located in the cylindrical housing portion 34 of the superheater, and the flights 48 of the screw provide a passageway for the steam from the inlet 36 to the conduit 40. A heater band 50 substantially surrounds the outside of the cylindrical housing 34 between the steam inlet 36 and outlet 40. A drain cock 52 is provided in the bottom of the superheater 24, and consists of a threaded plug 54 in hole 56. This plug may be removed periodically to drain any condensate from the heater. The screw 46 is fixed in place in the hollow portion 34 by bolts 58.

Steam is metered in to the superheater 24 at substantially atmospheric pressure by regulating valve 62. The steam entering the bottom of housing 34 is rapidly and efficiently heated as it follows the heated flights 48 of the screw 46 to the outlet 40. This superheated steam is fed through conduit 40 and jets 44 into stutter box 22 to set the crimp in the yarn 16b. Any condensate which might form can be drained by removing plug 54 periodically and allowing the condensate to drain out of the bottom of the heater. If the draw-crimper unit is shut down for any reason, the steam can be shut ed by valve 60.

Operation Referring to FIG. 1, the invention operates as follows: The multifilament yarn (e.g. nylon 6) 16 is unwound from the package (not shown) at about 125 to 200 yards per minute, fed around tensioning device 26, and then wrapped at least 3 times around the first set of godet rolls 14. The yarn is heated at this station by sliding contact with heated block 15, so as to be able to maintain a relatively high stretch ratio while substantially preventing breakage of the individual filaments. The temperature of block -15 ranges from 140 to 270 F. depending on the characteristics of the yarn. Because of the relatively long contact time of the yarn with the block 15, it need never be heated to a temperature above the melting point of the yarn.

The yarn 16 is then led over draw pin 18 and subsequently several times around draw rolls 20 which operate at a peripheral speed ranging from 2.5 to times, that of the first set of rolls 14. The draw rolls serve to stretch the yarn from 2.5 to 5 times, its original length, with the stretching being localized over a small area adjacent draw pin 18. The draw pin is provided in this process to prevent slippage of the yarn relative to godet rolls 14 and to localize the stress at the pin. This provides stretched filaments each having a substantially uniform cross section, which in turn enhances the crimp characteristics of the crimped fiber bundle 16b. When the yarn 16a leaves draw rolls 20, it is then fed into stutter 'box 22 where it is crimped :and further heated by superheated steam being fed through conduit 40 to the suifer box at substantially atmos pheric pressure and a temperature in the range of 220 to 300 F. The steam is superheated in a controlled manner such that the final moisture content of the yarn is maintained within a range of /2%. The crimped yarn 16b is withdrawn under tension and wound onto cone 28 at a rate of 500 to 700 yards per minute based on the drawn length of the yarn. The tension applied to the yarn will range from .001 to .07 gm. per denier, preferably from .03-.06 gram per denier, and should be suflicient to stretch the crimped yarn 1612 back to about to 99.5%, preferably to 99.5% of its original drawn length. This yarn may then be easily processed on textile equipment; and subsequently, by the application of steam and/or heat, bulked back to the desired crimp level due to the memory of deformation imparted by the initial steam treatment.

Embodiment of FIG. 3

FIG. 3 shows an embodiment in other ways similar to FIG. 1 except that the superheater 24 is connected to a steam box 32 located between draw rolls 20 and the entrance to stulfer box 22. The yarn \16a is fed through the steam box 32 and heated with superheated steam prior to being fed into the stufl er box. The fact that the steam heat is generally applied to the yarn prior to its being fed into the stulfer box provides a controlled amount of moisture and a controlled temperature prior to crimping. Thus, substantially constant friction is maintained between the nip rolls 30 and the yarn 16a thus giving a substantially constant crimp level. Also, the pre-steaming step makes the yarn more flexible before it is fed into the stulfer box, thus yielding a crimped yarn characterized by a very uniform bulk.- I

In the FIG. 3 embodiment, the steam box 32 is located between draw rolls 20 and nip rolls 30. The steam chamber 33 is provided with guideways 64, 64a for the yarn 16a. An inlet 66 is provided adjacent the bottom of the a chamber to provide a passage for the steam from'superheater 24. An undercut 70 is provided in the chamber 33 and a plug 69 blocks passage of the steam directly into the chamber so that the steam is fed in behind the yarn and over a relatively wide area to prevent local hot spots. A drain pipe 72 is provided in the bottom of steam chamber to provide an outlet for excess steam and any condensate that might be formed.

The steam box 32 includes rear body portion 74 and a door portion 76 hinged to rear portion by hinge 78. A latch 80 is provided to maintain the door closed tightly against seal 82 during operation, but to allow access to the interior of the steam chamber for inspection, maintenance, threading yarn, etc.

In operation, the yarn 16a is fed through guideways 64, 64a of steam box 32 and then into stuffer box 22. Superheater steam at substantially atmospheric pressure is fed into chamber 33 through inlet 66. This steam enters chamber 33 at a temperature ranging from 220 to 300 F. The incoming steam is directed through undercut 70 so that it is diffused generally throughout steam chamber 33. Alternatively plug 69 can be removed, thus allowing part of the steam to be directed upwardly by baflie 68. Excess steam and condensate exit through drain 72. The heated yarn 16a wtih a controlled moisture content is then fed from the steam box 32 to stufier box 22 where it is crimped and subsequently wound under tension.

Summary From the above, it is seen that this invention provides a rapid, simple and economical process for draw-crimping yarn in a single continuous operation.

While exemplary embodiments of the invention have been set forth in detail, the foregoing description is to be considered exemplary rather than limiting; and the scope of the invention is to be determined from the appended claims.

What is claimed is:

1. A process for draw-crimping multifilament yarn' in a single continuous operation; said yarn having 30 to 250 fibers per bundle and a denier per fiber of 6-25; the process comprising the steps of:

n ti y en iqni g th y feeding the yarn at least three times around a first set of rolls;

heating the yarn at the first set of rolls;

drawing the yarn about a draw pin;

feeding the yarn several more times around a set of draw rolls to draw out the heated yarn to a length ranging from about 2 to 9 times that of its original length;

thence feeding the yarn into a stutter-crimper where it is crimped, the crimp being set due to the application of heated vapor,

and subsequently withdrawing the crimped yarn from said stuffer crimper, and winding same under tension onto a package so that the yarn is stretched back to at least 85% of its original drawn length;

the time lapse between the exit of the stufi'er box and the package being at least sufficient to allow the yarn to cool to below about 110 F.

2. The process of claim 1 wherein:

the temperature of the yarn is controlled within :2 F.

at the first set of rolls;

the yarn is drawn to a length ranging from 2.5 to 5 times its original length;

the heated vapor is superheated steam;

the crimped yarn is withdrawn from the stuffer crimper under sufiicient tension to stretch it back to at least 95% of its original drawn length;

the yarn is processed at a rate of 500 to 700 yards per minute based on the drawn length of the yarn;

the time lapse between the exit of the stufier box and the package being sufiicient to cool the yarn to at least 85 F.;

and the total time lapse from the initial unwinding of the undrawn yarn from the supply package to the windup of the drawn crimped yarn onto the final package does not exceed 20 seconds.

3. The process of claim 2 wherein the steam is at substantially atmospheric pressure and is at a temperature of about 220 F. to 300 F.

4. The process of claim 2 wherein the yarn is steam treated prior to its being fed into the stufier crimper and wherein the moisture content of the yarn is maintained within a range of /2 5. The process of claim 2 wherein the yarn is steam treated while it is in a crimped state in the stutfer crimper.

6. Apparatus for draw-crimping multifilament yarn in a single continuous operation comprising:

tensioning means to initially tension the yarn prior to its being worked;

a first set of rolls designed to operate at a predetermined peripheral speed;

heating means associated with said rolls;

a second set of rolls designed to operate at a peripheral speed ranging from 2-9 times the peripheral speed of the first set of rolls;

a draw pin located between said first and second set of rolls;

a stufier box located behind said second set of rolls;

and means for winding said yarn under tension;

a vapor heater located between said second set of rolls and said winding means designed to heat and feed hot vapors into contact with said yarn;

said above elements all being operatively associated with one another to provide a continuous operation;

whereby yarn is drawn from said tensioning means over said first set of rolls and said heating means, around said draw pin, over said second set of rolls, fed into said stutfer box to be crimped, and subsequently wound under tension to substantially withdraw the crimps from the yarn;

said heater means feeding said vapor into contact with the yarn to heat same subsequent to said second set of rolls and prior to the yarn being removed from said stutter box.

7. The apparatus of claim 6 wherein said vapor heater includes a heating chamber and a superheater;

said heating chamber includes means for diffusing vapors generally into said heating chamber;

and said superheater includes a screw portion, the flights of which provide a path for the vapor to be heated.

8. A heating box for heating multifilament yarn, said heating box comprising:

guideways at the bottom and top thereofi to provide an inlet and egress for yarn passing through said box;

a yarn heating chamber within said box;

conduit means located adjacent the bottom of said box and below said heating chamber;

and means for diffusing said vapors generally throughout said heating box as they are fed into the box via said conduit means;

whereby a substantially uniform temperature is maintained through said heating chamber.

9. The heating box of claim 8 wherein the mean for diffusing said vapors comprises an undercut located behind said bottom guideways to difiuse the vapors and direct them upwardly and behind the yarn.

10. The heater box of claim 8 including a hinged doorway which forms one side of the guideways and chamber, and allows free access thereto when open.

11. The heater box of claim 10 including a drain at the bottom of said box to allow drainage of any excess vapor or vapor condensate.

12. The heater box of claim 11 including a seal means substantially surrounding said chamber to provide a seal when said door is in its closed and latched position. I

13. A superheater for generating and feeding dry steam to heat multifilament yarn, said heating comprising:

a housing having a hollow chamber extending from top to bottom thereof;

a steam inlet adjacent the bottom thereof, a steam outlet conduit adjacent the top thereof, and a drain cock at the bottom thereof;

a screw member mounted in said hollow chamber in such a manner that the steam inlet and outlet are in communication with each other via the flights of the screw;

conduit means leading from said steam outlet to a confined chamber containing said yarn;

heating means operatively connected to said superheater;

whereby steam passing into the superheater through the steam inlet is superheated as it passes up around the flights of the screw to the steam outlet, and is subsequently fed to the confined chamber;

excess condensate being bled out of the drain cock at the bottom of said housing.

References Cited UNITED STATES PATENTS MERVIN STEIN, Primary Examiner. L. K. RIMRODT, Assistant Examiner. 

6. APPARATUS FOR DRAW-CRIMPING MULTIFILAMENT YARN IN A SINGLE CONTINUOUS OPERATION COMPRISING: TENSIONING MEANS TO INITIALLY TENSION THE YARN PRIOR TO ITS BEING WORKED; A FIRST SET OF ROLLS DESIGNED TO OPERATE AT A PREDETERMINED PERIPHERAL SPEED; HEATING MEANS ASSOCIATED WITH SAID ROLLS; A SECOND SET OF ROLLS DESIGNED TO OPERATE AT A PERIPHERAL SPEED RANGING FROM 2-9 TIMES THE PERIPHERAL SPEED OF THE FIRST SET OF ROLLS; A DRAW PIN LOCATED BETWEEN SAID FIRST AND SECOND SET OF ROLLS; A STUFFER BOX LOCATED BEHIND SAID SECOND SET OF ROLLS; AND MEANS FOR WINDING SAID YARN UNDER TENSION; A VAPOR HEATER LOCATED BETWEEN SAID SECOND SET OF ROLLS AND SAID WINDING MEANS DESIGNED TO HEAT AND FEED HOT VAPORS INTO CONTACT WITH SAID YARN; SAID ABOVE ELEMENTS ALL BEING OPERATIVELY ASSOCIATED WITH ONE ANOTHERR TO PROVIDE A CONTINUOUS OPERATION; WHEREBY YARN IS DRAWN FROM SAID TENSIONING MEANS OVER SAID FIRST SET OF ROLLS AND SAID HEATING MEANS, AROUND SAID DRAW PIN, OVER SAID SECOND SET OF ROLLS, FED INTO SAID STUFFER BOX TO BE CRIMPED, AND SUBSEQUENTLY WOUND UNDER TENSION TO SUBSTANTIALLY WITHDRAW THE CRIMPS FROM THE YARN; SAID HEATER MEANS FEEDING SAID VAPOR INTO CONTACT WITH THE YARN TO HEAT SAME SUBSEQUENT TO SAID SECOND SET OF ROLLS AND PRIOR TO THE YARN BEING REMOVED FROM SAID STUFFER BOX. 